'vquic/curl_msh3.c' and '-DCURL_DISABLE_SOCKETPAIR'

[gvanem]

I did this

Building libcurl with -DCURL_DISABLE_SOCKETPAIR and -DUSE_MSH3, gave me this link error:
curl_msh3.obj : error LNK2019: unresolved external symbol Curl_socketpair referenced in function cf_msh3_connect

Perhaps the code should be:

--- a/vquic/curl_msh3.c 2023-10-26 09:20:23
+++ b/vquic/curl_msh3.c 2023-10-27 09:48:17
@@ -863,13 +863,15 @@

   CF_DATA_SAVE(save, cf, data);

+#if !defined(CURL_DISABLE_SOCKETPAIR)
   if(ctx->sock[SP_LOCAL] == CURL_SOCKET_BAD) {
-    if(Curl_socketpair(AF_UNIX, SOCK_STREAM, 0, &ctx->sock[0]) < 0) {
+    if(wakeup_create(&ctx->sock[0]) < 0) {
       ctx->sock[SP_LOCAL] = CURL_SOCKET_BAD;
       ctx->sock[SP_REMOTE] = CURL_SOCKET_BAD;
       return CURLE_COULDNT_CONNECT;
     }
   }
+#endif

   *done = FALSE;

since I see no other direct call to Curl_socketpair() and (MSH3 is for non-Windows too).

Not sure, but other places this is wrapped inside a #ifdef ENABLE_WAKEUP.

I expected the following

The .DLL to link.

curl/libcurl version

8.5.0-DEV

operating system

Win-10.

[bagder]

First: disabling the IPC communication with msh3 seriously cripples how it works and frankly, I am not convinced allowing this is a good idea. If you want to use msh3, you want it used. It might make sense to rather create an error that says so.

A complete fix to make this code use the wakeup_-macros instead of hardcoded socketpair also needs to usewakeup_write, wakeup_read and wakeup_close.

[gvanem]

I am not convinced allowing this is a good idea.

This combo? Fine by me, but where should the error be generated?

[bagder]

This combo? Fine by me, but where should the error be generated?

I think maybe in msh3.c, because I believe it is msh3's design that makes socketpair/pipe necessary.

[icing]

Something like this maybe?

--- a/lib/vquic/curl_msh3.c
+++ b/lib/vquic/curl_msh3.c
@@ -46,6 +46,10 @@
 #include "curl_memory.h"
 #include "memdebug.h"

+#ifdef CURL_DISABLE_SOCKETPAIR
+#error "MSH3 cannot be build with CURL_DISABLE_SOCKETPAIR set"
+#endif
+
 #define H3_STREAM_WINDOW_SIZE (128 * 1024)
 #define H3_STREAM_CHUNK_SIZE   (16 * 1024)
 #define H3_STREAM_RECV_CHUNKS \

[bagder]

@icing yup!